A videoconferencing service is a multimedia service that integrates information such as voice, an image, and data for long-distance transmission. A service provided by the videoconferencing service is video conferencing, which may include three types of content: image, voice, and data. Video conferencing enables people to hear voice of an opposite party and see an image of the opposite party during remote communication, which enhances a sense of reality, a sense of intimacy, and a sense of presence during the communication. In addition, the videoconferencing service may be used in fields such as military, politics, economy, education, and health fields to fully exert its advantages of realness, high efficiency, and real-timeness to provide simple, convenient, and efficient means of communication, management, collaborative decision making, and the like.
A video conference service is a type of videoconferencing service, and is a communication manner in which a conference is held between two or more places by using a television technology and a device through a transmission channel. A video conference system in the prior art generally includes several parts, such as a terminal device and a multipoint control unit (MCU). The terminal device is generally directly operated by a user, and provides input and output of video, audio, and data signals and the like. The terminal device includes a video input and output device, an audio input and output device, a terminal processor, a terminal management system, and the like, and may be equipped with peripheral devices such as a sound console, a power amplifier, a screen, an electronic whiteboard according to service requirements of different users. Functions of the terminal device are to collect a live image signal, a voice signal, and a related data signal, perform compression coding and multiplexing, and then transfer the signals to a transmission channel, and to classify and decode received video conference signals to restore image, voice, and data signals for a receiving conference site. In addition, the terminal device also transmits a conference control signal of a conference to the MCU, and executes a control instruction of the MCU for the video conference system.
In the video conference system, the MCU is a control center of the video conference system. When a quantity of terminal devices participating in a conference exceeds two, the MCU must be used for control purpose, and all terminal devices need to connect to the MCU by using a standard interface. The MCU implements switching and mixing of an image and voice according to protocols such as international standards H.221, H.242, and H.243, and implement related functions such as control of all conference sites.
In the prior art, an MCU provides media switching of voice, video, and an auxiliary stream. A user can implement data communication of voice, video, and an auxiliary stream with the MCU by using a terminal device that supports voice, video, and an auxiliary stream. After terminal devices join a conference, users can hear voice of each other, see video images of each other, and see a slide shared by using an auxiliary stream. In addition, terminal devices in a video conference system can further implement data conference communication with a data conference server, where the data conference server is used to process a data service. Referring to FIG. 1, FIG. 1 is a structural diagram of a system that includes a video conference system and a data conference server in the prior art, where a web client and an Internet Protocol (IP) phone are terminal devices.
In the prior art, an MCU shares a slide in a manner of an auxiliary stream, and a data conference server shares a slide in a manner of sharing a data conference desktop. When both an MCU and a data conference server exist in a network, a gateway is required to support communication between an auxiliary stream on the MCU and a data conference on the data conference server. The gateway is used to complete signaling and media switching between the auxiliary stream and the data conference, so that a user who joins a video conference system by using an IP PHONE can see, in the manner of an auxiliary stream, a shared desktop of a user who joins a conference of the data conference server, and a user who joins the conference of the data conference server by using a web client can see, in the manner of sharing a data conference desktop, the auxiliary stream sent by the IP phone that joins the video conference system.
When a user accesses the MCU by using a terminal device that supports audio, video, and an auxiliary stream and the like, only one call is required between the terminal device and the MCU. However, if the user joins the video conference system by using multiple terminal devices, and each terminal device supports only one media type, the multiple terminal devices need to separately establish one call with the MCU. In this case, one user establishes multiple calls, and multiple ports of the MCU are occupied, which wastes port resources of the MCU.